From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422712AbXCBBoG (ORCPT ); Thu, 1 Mar 2007 20:44:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422710AbXCBBoG (ORCPT ); Thu, 1 Mar 2007 20:44:06 -0500 Received: from tmailer.gwdg.de ([134.76.10.23]:56297 "EHLO tmailer.gwdg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422712AbXCBBoE (ORCPT ); Thu, 1 Mar 2007 20:44:04 -0500 Date: Fri, 2 Mar 2007 02:43:41 +0100 (MET) From: Jan Engelhardt To: Sindre =?iso-8859-1?b?QWFt5XM=?= cc: linux-kernel@vger.kernel.org Subject: Re: Correct way for an application to sleep? In-Reply-To: <20070224215403.ka5imjqjo08cko0c@webmail.ntnu.no> Message-ID: References: <20070224215403.ka5imjqjo08cko0c@webmail.ntnu.no> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Feb 24 2007 21:54, Sindre Aamås wrote: > >Without root-privilegies, that leaves general purpose sleep functions >like nanosleep afaik. The problem is that the granularity of these >seems very unpredictable, and if I am to use a lowest common >denominator I'd only be able to sleep like 10 ms pr 16.7 ms on fast >systems, and not at all on not so fast systems. So, I'd like to know >what the "correct" way to handle this kind of situation is, if any, >from a kernel perspective. Is the only sensible thing to do to give a >user settable preference, deciding on a compromise default (or one >that says "screw you old kernels")? You could use an adaptive sleeping ('overhead-corrected'), but I do not know how well it works with asynchronous events (such as audio output). Take a look at the usleep_ovcorr() function in http://ttyrpld.svn.sf.net/viewvc/*checkout*/ttyrpld/trunk/user/replay.c Jan -- ft: http://freshmeat.net/p/chaostables/